docs: def get_transformer(name, base=None, *args, **kwargs):
      ''' Scans list of currently available Transformer classes and returns an
      instantiation of the first one whose name perfectly matches
      (case-insensitive).
  
      Args:
          name (str): The name of the transformer to retrieve. Case-insensitive;
              e.g., 'stftextractor' or 'CornerDetectionExtractor'.
          base (str, list): Optional name of transformer modules to search.
              Valid values are 'converters', 'extractors', and 'filters'.
          args, kwargs: Optional positional or keyword arguments to pass onto
              the Transformer.
      '''
  
      name = name.lower()
  
      # Default to searching all kinds of Transformers
      if base is None:
          base = ['extractors', 'converters', 'filters']
  
      base = listify(base)
  
      for b in base:
          importlib.import_module('pliers.%s' % b)
          mod = getattr(pliers, b)
          classes = getattr(mod, '__all__')
          for cls_name in classes:
              if cls_name.lower() == name.lower():
                  cls = getattr(mod, cls_name)
                  return cls(*args, **kwargs)
  
      raise KeyError("No transformer named '%s' found." % name)